Hydraulic fracturing can increase the rate of production of oil and gas from low-permeability reservoirs. Hydraulic fracturing increases the permeability of reservoir rocks by opening channels through which oil and gas can travel to recovery wells. During hydraulic fracturing, a fluid is pumped through a wellbore under high pressure into a subterranean reservoir where it splits or fractures the reservoir rock. A proppant, like sand, is often added to the pumped fluid and carried in suspension into the newly formed fractures. When pumping ceases, the fractures partially close on the proppant, leaving open channels for oil and gas to flow to the recovery well, i.e., the wellbore through which the fracture fluid was originally pumped.
High-pressure pumps are used to complete hydraulic fracturing procedures or “frac jobs.” These pumps have “fluid ends” within which a number of reciprocating plungers pressurize a fracture fluid. Suction and discharge valves control fluid flow to, and from, the plungers. A valve that has too many internal projections can capture or “knock out” enough proppant to block the flow of fluid through a pump, requiring that time and effort be invested to clear the blockage and repair any damage to the pump—a costly undertaking. Also, tortuous flow pathways through valves can create substantial pressure losses that require more energy to be expended by a pump than is necessary to perform hydraulic fracturing work.
Commonly used discharge valves possess a number of guides or “wings” that project into the center of a valve to hold a piston in place. These wings are known to capture proppants suspended in fracture fluids. A need exists for an improved, discharge valve without wings.